Iohexol contrast medium induces QT prolongation in amiodarone patients.

Author(s): Goernig M, Kirmeier T, Krack A, Hartog CS, Figulla HR, Leder U

Affiliation(s): Friedrich-Schiller-University, Clinic of Internal Medicine III, Erlanger Allee 101, D-07740 Jena, Germany. Matthias.Goernig@med.uni-jena.de

Publication date & source: 2004-07, Br J Clin Pharmacol., 58(1):96-8.

Publication type: Clinical Trial; Randomized Controlled Trial

AIMS: Amiodarone is widely used in ventricular tachyarrhythmias and atrial fibrillation, known to prolong QT-intervals. Concurrent administration of drugs prolonging QT- time can induce life-threatening ventricular tachyarrhythmia. METHODS: QT-interval changes following use of Iohexol contrast-medium for coronarangiography were observed comparing 21 patients taking long-term amiodarone therapy with 21 controls not taking amiodarone or QT-prolonging drugs retrospectively. RESULTS: Concurrent use of Iohexol and amiodarone was associated with significant prolongation of QTc-interval (433, 95%CI: 419-448 ms vs. 480, 95%CI: 422-483 ms, P < 0.001) the day after coronarangiograpgy. 6/21 patients showed severe prolonged QTc-interval of >500 ms. CONCLUSION: Caution is advised until more is known about pro-arrhythmic effects of Iohexol.